Recent developments of ultra-wideband (UWB) technology have found use in radio communication systems primarily in a frequency band from 3.1 GHz to 10.6 GHz. UWB radios communicate with short pulses or cycles on the order of nanoseconds, spreading energy over a wide range of bandwidth. Currently available high frequency and large bandwidths of UWB radios may potentially provide high speed data communication and other applications. However, due to UWB's unlicensed use and wide spectrum, interference between different UWB radios may be present during communication and may have severe impact on communication quality between UWB radios.
To minimize the impact of the interference, UWB applications often use direct sequence spread spectrum technology or frequency hopping technology. Since frequency hopping technology requires both the radio transmitter and the radio receiver to hop over different bands of frequencies, a high-degree of synchronization between the transmitter and the receiver may be needed.
A successful direct sequence spread spectrum system, on the other hand, often relies on high processing gain (i.e., spreading factor) of the communication system to overcome interference. When the bit-rate of the communication system increases, the spreading factor of conventional spread spectrum system may decrease. For example, for a binary phase shift keyed (BPSK) system, when the communication bit rate reaches 200 Mbps, the spreading factor for the entire UWB spectrum (i.e., 3.1 GHz to 10.6 GHz) may be only 37.5, which may not be sufficient for a commercial communication system to overcome interference among multiple users.
Methods and systems consistent with certain features of the disclosed embodiments address one or more of the problems set forth above.